Ultrastructural investigation of lead-induced intranuclear inclusion bodies in mice

The effect of chronic lead exposure on the course of schistosomiasis in hamsters and the protective effect of the antioxidant preparation ‘Antox’

Eighty adult male hamsters were used in this study, 20 of them were divided equally into a noninfected, nontreated control group and chronic lead exposed groups, which were given lead acetate intraperitoneally, dissolved in distilled water, 2 mg/kg/day for seven weeks. Then, two experiments were carried out on the remaining animals. Each experiment included 30 animals and was divided equally into three groups. Experiment A was carried out on the following groups: Schistosoma mansoni infected group, S. mansoni infected and chronic lead exposed group and S. mansoni infected, chronic lead exposed and ‘Antox’ treated group. Experiment B was done following the same design except that infection was carried out using Schistosoma haematobium cercaria. Chronic lead exposure of Schistosoma infected groups showed significant reductions in worm burden, tissue egg load and ova excretion in stool, liver and intestine. Compared with the control group, there were insignificant increases in serum and hepatic glutathione and malondialdehyde levels and a significant increase in hepatic 8-oxodeoxy guanosine phosphate (8-Ox-Dg) levels in Schistosomainfected groups. However, there was a significant increase in hepatic and blood lead levels, oxidative stress parameters and in the hepatic 8-Ox-Dg level in Schistosoma infected and chronic lead exposed groups as compared with their corresponding Schistosoma only infected groups. This study revealed a significant reduction in oxidative stress parameters as well as in blood and hepatic lead levels and in hepatic 8-Ox-Dg levels after giving Antox to the Schistosoma infected and chronic lead exposed groups. However, Antox increased insignificantly all the parasitological parameters studied in the Schistosoma infected and chronic lead exposed groups.

Intranuclear Inclusions in Renal Tubular Epithelium in Immunodeficient Mice Stain with Antibodies for Bovine Papillomavirus Type 1 L1 Protein

The kidneys from six immunodeficient mice examined by Cerberus Sciences and the Animal Resources Centre, displayed karyomegaly with pale eosinophilic, intranuclear inclusions upon histopathological examination. Electron microscopy performed on kidney tissue from 5/6 mice demonstrated margination of the chromatin in large nuclei. Laboratory tests were used to detect nucleic acid of papillomaviruses, polyomaviruses, circoviruses and anelloviruses (4/6 mice), a specific PCR was used to detect murine polyomavirus (1/6), and a panel of serological tests was used to detect seroconversion to major murine pathogens (1/6). All molecular and serological tests were negative. Immunohistochemistry using polyclonal anti-bovine papillomavirus type 1 (BPV-1) L1 antibody, Camvir monoclonal anti-papillomavirus antibody (directed against the seven amino acids GFGAMDF found in human papillomavirus (HPV) 16 L1 protein), a commercially available mixture of two monoclonal antibodies, anti-BPV-1 L1/1H8 + Camvir antibodies, and a monoclonal anti-Hsc70 antibody revealed specific, positive staining of murine renal tubular epithelial intranuclear inclusions in 6/6 mice using the anti-BPV-1 L1 containing antibodies only. Methyl pyronin green, PAS and Feulgen histochemical reactions revealed that the intranuclear inclusions did not consist of RNA, DNA or carbohydrate. An immunohistochemical method now exists that can be used to confirm and evaluate suspected cases of murine inclusion body nephropathy.

Cadmium- and lead-induced apoptosis in mallard erythrocytes (Anas platyrhynchos)

Cadmium, lead and cadmium-lead (1:10) induced apoptosis were studied using mallard blood cells. The allowable range in concentrations were: 0.01-0.5, 0.1-5.0, and 0.01:0.10-0.50:5.00 mM, for cadmium, lead and cadmium-lead, respectively. The lowest EC(50) achieved was for cadmium (0.22+/-0.04 mM). Two doses from each treatment group were chosen to study apoptosis and the presence of metals in cells. The percentage of apoptotic cells increased as the concentration of metals increased. The percentage of cells with intracellular metals was high for both exposure levels and the quantity of intracellular metal was greater for exposure to high concentrations. Morphological alterations for all types of exposure were related to the diverse range of effects that these metals have on membranes. We suggest that the decrease in the number of erythrocytes observed in specimens suffering from lead and cadmium poisoning is related to the induction of apoptosis.